Watch

The watchmaking industry is the sector where pad printing originated, and to this day, it remains one of the most demanding fields in which this technology is applied. Numerous components of a wristwatch are refined using pad printing – from the dial and various complications, such as date, day, moon phase, or world time displays, to the case back. For all these applications, the machines must operate with exceptional precision to achieve the required quality.

Single-Color Printing – Example: Date Disc

In single-color printing, such as on the date disc, a ring where the numbers 1 to 31 are printed, repeat accuracy plays a crucial role. The text is extremely small, with line widths of approximately 0.1 mm. Even a misalignment of just 0.05 mm between two prints would make the line appear 50% thicker, which is clearly visible to the naked eye. Since the numbers are arranged in a circular pattern, such an error would make the text appear thicker at the top and bottom compared to the sides – an effect that is immediately noticeable.

To achieve the required quality, repeat accuracy of ±0.01 mm or better is necessary. Many of our machines meet this requirement. This level of precision is also needed when positioning the single-color print on the component. More cost-effective options use highly precise cross tables that can be adjusted in increments of 0.01 mm. In contrast, standard cross tables typically allow adjustments only in 0.1 mm steps.

Multi-Color Printing and Complex Positioning

For multi-color printing or precise placement of multiple images on a product, simple pad printing machines are unsuitable. Here, the positions must be accurately controlled via motors, as seen in the ML series machines. In addition to XY positioning, angular precision is equally critical. Ideally, this should also be adjustable electrically with the same level of accuracy.

Watch dials can range from simple single-color designs to intricate artworks with over 20 colors. A particular challenge is printing with luminous colors. The required luminous paint, such as SuperLuminova, is applied in numerous layers. It is essential to avoid smearing during this process.

Cleanliness in the Printing Process

When producing date discs, day discs, or other complications, a white surface is often printed on a ring or circle first to create a uniform glossy finish. To ensure no dust contaminates the process, printing is often conducted in a cleanroom. Alternatively, the pad printing machine can be equipped with a laminar flow system. This system continuously supplies filtered, clean air into the machine, preventing dust particles from entering the printing process.

Case Back Printing

The case back of a watch, which provides a view of the internal mechanism, can also be decorated. Often, this involves various marking processes that must be perfectly aligned. Accurate and reliable printing is only achievable with camera-assisted positioning.

Conclusion

Printing on watch components not only demands exceptional precision but also involves addressing a variety of challenges, depending on the specific application and part. This combination makes the watchmaking industry the pinnacle of pad printing expertise.